216 
BKITISH PHARMACEUTICAL CONFERENCE. 
water of crystallization is expressed by the formula ; but the distinguishing; 
characters are only applicable to the hydrated salt, and the prescribed quan¬ 
titative test accurately denotes the percentage of morphia in the crystals. 
The fourteen different formulae representing chlorides and hydrochiorates 
might, therefore, be safely excluded from the Pharmacopoeia; and if the pre¬ 
fix hi- in the name “ bichloride of platinum” were omitted, and the one word 
“ crystallized” added to the name “ chloride of barium,” there could be no 
mistake as to any one of the fourteen compounds named. In place of the 
secondary descriptive scientific names of calomel and corrosive sublimate,— 
“subchloride of mercury” and “chloride of mercury,”—it would be advi¬ 
sable to employ the unobjectionable appellations “ mercurous chloride” and 
“mercuric chloride,” which are coming into general use among chemists of 
both the old and the new schools. In the definition of “ solution of perchlo- 
ride of iron,” a similar alteration might be advantageously made by substitu¬ 
ting the term “ ferric chloride ” for “ perchloride of iron.” 
Bromide. —The name “ bromide of potassium ” in the Pharmacopceia indi¬ 
cates plainly enough the only combination of bromine and potassium. 
Iodides. —The names of the four officinal iodides are sufficiently distinc¬ 
tive. “ Iodide of potassium” is the accepted name of the only compound of 
iodine with potassium. Both mercurous and mercuric chlorides are officinal, 
but they are plainly distinguished by the names “ green iodide of mercury ” 
and “ red iodide of mercury.” The compound called “ iodide of iron ” is the 
ferrous iodide, but, as there is no definite crystallizable ferric iodide, it is 
unnecessary to indicate the fact by any prefix to the generic name “ iodide.” 
According to the formula given in the Pharmacopoeia, the crystalline ferrous 
iodide is a definite hydrate, containing four combining proportions of water. 
If it be necessary to indicate this degree of hydration, the simple statement 
that the compound contains 18‘85 per cent, of water might be substituted foy 
the formula. 
Cyanides. —The names of the three compounds containing cyanogen gre 
unambiguous. “ Hydrocyanic acid ” is the accepted name for the only cyaur 
ide of hydrogen. The compounds called “ ferridcyanide ” and “ ferrocyanide” 
are well known, and satisfactorily distinguished by their common sy¬ 
nonyms, “red prussiate” and “ yellow prussiate of potash.” The addition 
of the word “ crystallized ” to the name of the latter salt would imply what 
the formula expresses, namely that three molecules of water are combined 
with one molecule of the anhydrous salt. The crystals of the red salt contain 
no water. 
Sulphides and Sulphydrates .—The sulphide of hydrogen and sulphydrate 
of ammonium, which are prescribed as tests, are called “ sulphuretted hydro¬ 
gen ” and “ hydrosulphuret of ammonia,” and the formulae given are unne¬ 
cessary additions to these well-understood and unobjectionable names. The 
compound termed “ sulphuret of iron ” is the ferrous sulphide ; and if this 
fact were stated as a definition, the formula might be omitted. The names 
“ tersulphuret of antimony” and “ tersulphuret of potassium,” which occur 
respectively in the definitions of “ sulphurated antimony ” and “ sulphurated 
potash,” do not clash with modern doctrines, and would be perfectly intelli¬ 
gible without the formulae. 
Oxides and Hydrates .—The normal oxides of hydrogen, silver, magnesium, 
zinc, calcium, and lead are plainly denoted by the names “ water,” “ oxide of 
silver,” “magnesia,” “oxide of zinc,” “lime,” and “ litharge.” It is true 
that oxygen unites with silver in three proportions, but argentous oxide and 
peroxide of silver are unstable compounds. Moreover the quantitative test 
which shows that 27 grains of silver are left on igniting 29 grains of the 
oxide, fixes the exact composition of the body. Again, there are several 
